Initial hydraulic failure followed by late-stage carbon starvation leads to drought-induced death in the tree Trema orientalis

Communications Biology

Shin-Taro Saiki¹  Yuri Kono¹  Atsushi Ishida¹  Fuku Kimura²  Masako Dannoura³  Jin Yoshimura⁴  Kenichi Yoshimura⁴  Shin-ichi Aikawa⁵  Kenichi Yazaki⁶ 

[1] Center for Ecological Research, Kyoto University, Otsu, Japan;Faculty of Agriculture, Kyoto University, Kyoto, Japan;Faculty of Agriculture, Yamagata University, Tsuruoka, Japan;Forestry and Forest Products Research Institute, Tsukuba, Japan;Graduate School of Bioresource Sciences, Nihon University, Fujisawa, Japan;Kyoto University Graduate School of Global Environmental Studies, Kyoto, Japan

DOI  :  10.1038/s42003-018-0256-7

学科分类：生物科学（综合）

来源: Nature Publishing Group

【 摘 要 】

Drought-induced tree death has become a serious problem in global forest ecosystems. Two nonexclusive hypotheses, hydraulic failure and carbon starvation, have been proposed to explain tree die-offs. To clarify the mechanisms, we investigated the physiological processes of drought-induced tree death in saplings with contrasting Huber values (sapwood area/total leaf area). First, hydraulic failure and reduced respiration were found in the initial process of tree decline, and in the last stage carbon starvation led to tree death. The carbohydrate reserves at the stem bases, low in healthy trees, accumulated at the beginning of the declining process due to phloem transport failure, and then decreased just before dying. The concentrations of non-structural carbohydrates at the stem bases are a good indicator of tree damage. The physiological processes and carbon sink-source dynamics that occur during lethal drought provide important insights into the adaptive measures underlying forest die-offs under global warming conditions.

【 授权许可】

CC BY